Objective/ Method/Outcome
Objective: Determines if the Outdoor Air Damper is open while the AHU Supply Fan is inactive.
Method: Compares the Outdoor Air Damper to the Supply Fan Status. If the Outdoor Air Damper is open while the Supply Fan Status signal is inactive, the hours of faulty operation are calculated.
Outcome: This rule generates an insight if the Weekly Hours of Faulty Operation exceeds the acceptable weekly threshold.
Description
Reference: ASHRAE36-5.16.4/5/6
This rule determines if outdoor air damper is closed when AHU is not operating. The consequence would be humidity building up in the duct work.
This rule is part of the CopperTree Standard rule-set. (Aliased Celsius / Aliased Fahrenheit)
Default Priority
Medium
Diagnosis
1. Inspect the equipment to see if it has been overridden manually.
2. Review control sequence.
Message
OAD is open when AHU is disabled
Rule Template
Insight Type: Fault Detection
Trigger Type: Active High
Notes
1. Expected values for “SF Status” inputs are “0” or “1”.
Default Values:
Const. – Threshold – Weekly Hours of Faulty Operation [Hrs]: 4
CTLs:
OAD Open, Fan Inactive – Weekly Hours of Faulty Operation (KPI)
OAD Open, Fan Inactive – Hours of Faulty Operation (CUSUM)
